From 062be1ab4768a2f481ce08fb95d0e417cb8b7251 Mon Sep 17 00:00:00 2001
From: Simon Warta <simon@warta.it>
Date: Thu, 29 Jun 2023 15:05:18 +0200
Subject: [PATCH 1/2] Add missing stats call

---
 CHANGELOG.md             | 4 ++++
 packages/vm/src/cache.rs | 1 +
 2 files changed, 5 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4aafbc2baf..66ff512359 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Fixed
+
+- cosmwasm-vm: Add missing cache stats increment when calling `pin`.
+
 ### Added
 
 - cosmwasm-std: Implement `BankQuery::AllDenomMetadata` to allow querying all
diff --git a/packages/vm/src/cache.rs b/packages/vm/src/cache.rs
index 85c145e15d..4f00e7430a 100644
--- a/packages/vm/src/cache.rs
+++ b/packages/vm/src/cache.rs
@@ -272,6 +272,7 @@ where
 
         // Re-compile from original Wasm bytecode
         let code = self.load_wasm_with_path(&cache.wasm_path, checksum)?;
+        cache.stats.misses = cache.stats.misses.saturating_add(1);
         let module = compile(&code, Some(cache.instance_memory_limit), &[])?;
         // Store into the fs cache too
         cache.fs_cache.store(checksum, &module)?;

From 053b5c9a91bdcfcbac7a2bab257e7d0b2cdb000e Mon Sep 17 00:00:00 2001
From: Simon Warta <simon@warta.it>
Date: Thu, 29 Jun 2023 15:41:04 +0200
Subject: [PATCH 2/2] Test recompiling modules from Wasm

---
 packages/vm/src/cache.rs | 60 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 59 insertions(+), 1 deletion(-)

diff --git a/packages/vm/src/cache.rs b/packages/vm/src/cache.rs
index 4f00e7430a..dbc809ef09 100644
--- a/packages/vm/src/cache.rs
+++ b/packages/vm/src/cache.rs
@@ -452,7 +452,7 @@ mod tests {
     use crate::errors::VmError;
     use crate::testing::{mock_backend, mock_env, mock_info, MockApi, MockQuerier, MockStorage};
     use cosmwasm_std::{coins, Empty};
-    use std::fs::{create_dir_all, OpenOptions};
+    use std::fs::{create_dir_all, remove_dir_all, OpenOptions};
     use std::io::Write;
     use tempfile::TempDir;
 
@@ -776,6 +776,36 @@ mod tests {
         assert_eq!(cache.stats().misses, 0);
     }
 
+    #[test]
+    fn get_instance_recompiles_module() {
+        let options = make_testing_options();
+        let cache = unsafe { Cache::new(options.clone()).unwrap() };
+        let checksum = cache.save_wasm(CONTRACT).unwrap();
+
+        // Remove compiled module from disk
+        remove_dir_all(options.base_dir.join(CACHE_DIR).join(MODULES_DIR)).unwrap();
+
+        // The first get_instance recompiles the Wasm (miss)
+        let backend = mock_backend(&[]);
+        let _instance = cache
+            .get_instance(&checksum, backend, TESTING_OPTIONS)
+            .unwrap();
+        assert_eq!(cache.stats().hits_pinned_memory_cache, 0);
+        assert_eq!(cache.stats().hits_memory_cache, 0);
+        assert_eq!(cache.stats().hits_fs_cache, 0);
+        assert_eq!(cache.stats().misses, 1);
+
+        // The second get_instance finds the module in cache (hit)
+        let backend = mock_backend(&[]);
+        let _instance = cache
+            .get_instance(&checksum, backend, TESTING_OPTIONS)
+            .unwrap();
+        assert_eq!(cache.stats().hits_pinned_memory_cache, 0);
+        assert_eq!(cache.stats().hits_memory_cache, 1);
+        assert_eq!(cache.stats().hits_fs_cache, 0);
+        assert_eq!(cache.stats().misses, 1);
+    }
+
     #[test]
     fn call_instantiate_on_cached_contract() {
         let cache = unsafe { Cache::new(make_testing_options()).unwrap() };
@@ -1220,6 +1250,34 @@ mod tests {
         cache.unpin(&non_id).unwrap();
     }
 
+    #[test]
+    fn pin_recompiles_module() {
+        let options = make_testing_options();
+        let cache: Cache<MockApi, MockStorage, MockQuerier> =
+            unsafe { Cache::new(options.clone()).unwrap() };
+        let checksum = cache.save_wasm(CONTRACT).unwrap();
+
+        // Remove compiled module from disk
+        remove_dir_all(options.base_dir.join(CACHE_DIR).join(MODULES_DIR)).unwrap();
+
+        // Pin misses, forcing a re-compile of the module
+        cache.pin(&checksum).unwrap();
+        assert_eq!(cache.stats().hits_pinned_memory_cache, 0);
+        assert_eq!(cache.stats().hits_memory_cache, 0);
+        assert_eq!(cache.stats().hits_fs_cache, 0);
+        assert_eq!(cache.stats().misses, 1);
+
+        // After the compilation in pin, the module can be used from pinned memory cache
+        let backend = mock_backend(&[]);
+        let _ = cache
+            .get_instance(&checksum, backend, TESTING_OPTIONS)
+            .unwrap();
+        assert_eq!(cache.stats().hits_pinned_memory_cache, 1);
+        assert_eq!(cache.stats().hits_memory_cache, 0);
+        assert_eq!(cache.stats().hits_fs_cache, 0);
+        assert_eq!(cache.stats().misses, 1);
+    }
+
     #[test]
     fn loading_without_extension_works() {
         let tmp_dir = TempDir::new().unwrap();